false marketing

I was offered Vodacom contract by a gentleman, the contract was a R120 a month which include a vodaphone smart turbo 7 and R600 voucher, on the day of delivery the was no voucher. contacted Vodacom and they knew nothing about the company that offered me a contract and I requested that the contract should be cancelled as the was no way forward, within an hour I received a call from the same company that offered me a phone they advised the voucher was going to be delivered on the 22/06/2018 and the could have been an mistake that voucher fell off during packing of the phones, today is the 28/06/2018 still no call or delivery, I called Vodacom and Vodacom takes me from pillar to post and finally the dropped the line and I was left hanging. my question is how can Vodacom be in business with the people that they do not know or have communication with?